While the board templates are not yet officially available via our API, you should be able to work around this by using the idBoardSource parameter and the keepFromSource one in order to create a new board based on an existing one.
So your call would look like this:
curl --request POST \ --url 'https://api.trello.com/1/boards/?name=BoardName&defaultLabels=true&defaultLists=true&idBoardSource=BOARDID&keepFromSource=cards&prefs_permissionLevel=private&prefs_voting=disabled&prefs_comments=members&prefs_invitations=members&prefs_selfJoin=true&prefs_cardCovers=true&prefs_background=blue&prefs_cardAging=regular&key=yourAPIkey&token=yourToken'
where BoardName is the name you want to give to that new board, and BOARDID is the actual ID of the board that you can retrieve via the API (https://developers.trello.com/reference/#boardsboardid-1).
This will also work if the BOARDID is from a board template :)
If you had to thrive a new habit during a lockdown, what would it be? Trello
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events